In the water cycle, after evaporation, through which process does water vapour form clouds?

Correct answer: Condensation

Direct answer: A, condensation. In the water cycle, heat causes liquid water from oceans, lakes, rivers and soil to evaporate into water vapour. The vapour rises and usually cools in the atmosphere. Cooling changes the vapour into tiny liquid droplets or, under suitable conditions, ice crystals. These suspended particles gather to form clouds; this change is called condensation. B, weathering, is the breakdown of rocks at or near Earth’s surface and is not the cloud-forming step. C, runoff, is water flowing over land toward streams, lakes or the sea, usually after precipitation; it is a later movement of liquid water. D, filtration means passing a fluid through a material that removes particles, and it is not a normal atmospheric process in cloud formation. The basic sequence to remember is evaporation, cooling, condensation, cloud formation, precipitation and collection or runoff. Memory cue: vapour rises, cools and condenses into cloud droplets. Do not confuse condensation with precipitation: condensation forms droplets, while precipitation is their later fall when they become sufficiently large.